Viewing the Launch by Webcast: The live webcast will begin at 1:01 p.m. EDT.

Mission Description: GPS satellites serve and protect our warfighters by providing navigational assistance for U.S. military operations on land, at sea, and in the air. Civilian users around the world also use and depend on GPS for highly accurate time, location, and velocity information.

GPS IIF-8 is one of the next-generation GPS satellites, incorporating various improvements to provide greater accuracy, increased signals, and enhanced performance for users.

Launch Notes: GPS IIF-8 will be ULA’s fourth GPS launch of 2014 and the 12th of the year. The mission will mark ULA’s 89th mission launched since the company was founded in 2006.

Launch Updates: To keep up to speed with updates to the launch countdown, you can call the ULA launch hotline at 1-877-852-4321 or join the conversation at www.facebook.com/ulalaunch and twitter.com/ulalaunch; look for the #GPSIIF8 hashtag.

The Atlas V 401 that will launch the GPS IIF-8 mission for the U.S. Air Force rolls out on Tuesday at Space Launch Complex (SLC)-41 at Cape Canaveral Air Force Station, Fla. (SpaceCoastDaily.com image)